A question that comes across most people's minds when they look to upgrade to a home theater is whether they can use any of their existing A/V gear in their new home theater.
The answer usually is, "Well, you probably can, but you lose a lot by doing so (unless the gear is less than 2 years old, and in some cases, even that's too old)." If you're thinking about using existing equipment, consider the following:
* TVs: If it's smaller than a 27-inch display, why bother? Home theater needs a big-screen display for maximum effect. The most important thing to consider when reviewing the capabilities of your old TV is this: Can it display HD (high-definition) pictures? If not, then consider an upgrade. Also, check for features such as picture-in-picture, and make sure your TV has the right kinds of inputs to accept the latest and greatest source devices. Look for High-Definition Multimedia Interface (HDMI) or Digital Video Interface (DVI) inputs.
TV size requirements are actually a mix of three things: the size of the display, the display's resolution (or number of individual picture elements that make up the picture on your screen), and your viewing distance from the screen. For most home theaters, a bigger display is better, but if you're planning to view the screen from a relatively short distance (a few feet, for example), you may be better off with a relatively small screen.
* Receivers: Chances are your receiver is an audio (stereo) receiver, which probably doesn't have surround sound processing capability, inputs for video gear, or built-in amplifiers for your surround sound speakers. You can use an audio-only receiver as an amplifier to drive some speakers, but if you want to listen to the latest surround sound capabilities, which are encoded on most DVDs, you'll need a new audio/video receiver, period. What's more, if you have a lot of video sources, you're going to want to switch among them - and for that, you need a receiver with sophisticated video switching.
* VCRs: As long as your VCR is a VHS HiFi VCR, it's just fine. But it can't replace a DVD player, which has about four times the picture resolution of a VCR (meaning the picture is about twice as sharp and detailed).
* CD players: Your CD player will probably work fine with your home theater setup. Depending on your space constraints, however, you might just use your DVD player to play your CDs because it can.
* DVD players: Your DVD player will probably play fine in your new home theater, but if it can't record, you'll miss out. With the latest personal video recorders (PVRs), you can archive and offload all sorts of content to DVDs, and for that, you want a DVD player/recorder to burn the DVDs. Keep in mind that you can often use a PC (with the right software onboard) to record DVDs, too.
* Speakers: Your current speakers might not be very useful unless it's a set of speakers, not ones that you piece together. Speakers work in tandem and therefore should have a similar foundation of performance. If you have a pair of stereo speakers that you can match into a complete set of surround sound speakers from the same manufacturer, you may be able to use what you have. (Be sure to choose additional speakers that are timbre-matched with your existing speakers.)
* Other stuff: Most other gear can work with your system - turntables, cassette decks, laser disc players, and so on. You can usually plug them in and play them without problems.
* Internet connection: Okay, your Internet connection isn't gear in the traditional sense, but still, if you're using a dialup connection, you should seriously consider upgrading to broadband if you want your home theater to take advantage of the Internet. As present and future consumer devices become increasingly reliant on the Internet for accessing information and content, you'll need a broadband connection to download this content.
http://tech.yahoo.com/gd/using-existing-gear-for-a-new-home-theater/200235;_ylt=AiRoqejsF0sjpYrzgbeZLwgSLpA5
